title: The correlation between the levels of tissue inhibitor of metalloproteinases 1 in plasma and tumour response and survival after preoperative radiochemotherapy in patients with rectal cancer.
abstract: BACKGROUND
  The aim of this study was to analyse whether the level of tissue inhibitor of metalloproteinases (TIMP) 1 is associated with the tumour response and survival to preoperative radiochemotherapy in rectal cancer patients.
  
  
  METHODS
  Ninety-two patients with histologically confirmed non-metastatic rectal cancer of clinical stage I- III were treated with preoperative radiochemotherapy, surgery and postoperative chemotherapy. Plasma TIMP-1 concentrations were measured prior to the start of the treatment with an enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Median follow-up time was 68 months (range: 3-93 months) while in survivors it was 80 months (range: 68-93 months). The 5-year locoregional control (LRC), disease-free survival (DFS), disease-specific survival (DSS) and overall survival (OS) rates for all patients were 80.2%, 56.4%, 63.7% and 52.2%, respectively. The median TIMP-1 level was 185 ng/mL (range: 22-523 ng/mL) and the mean level (±standard deviation) was 192 (±87) ng/mL. Serum TIMP-1 levels were found to be significantly increased in patients with preoperative CRP>12 mg/L and in those who died from rectal cancer or had cT4 tumours. No correlation was established for age, gender, carcinoembriogenic antigene (CEA) level, platelets count, histopathological grade, response to preoperative therapy, resectability and disease reappearance. On univariate analysis, various parameters favourably influenced one or more survival endpoints: TIMP-1 <170 ng/mL, CRP <12 mg/L, platelets count <290 10E9/L, CEA <3.4mg/L, age <69 years, male gender, early stage disease (cN0 and/or cT2-3), radical surgery (R0) and response to preoperative radiochemotherapy. In multivariate model, LRC was favourably influenced by N-downstage, DFS by lower CRP and N-downstage, DSS by lower CRP and N-downstage and OS by lower TIMP-1 level, lower CRP and N-downstage.
  
  
  CONCLUSIONS
  Although we did not find any association between pretreatment serum TIMP-1 levels and primary tumour response to preoperative radiochemotherapy in our cohort of patients with rectal cancer, TIMP-1 levels were recognized as an independent prognostic factor for OS in these patients.
authors.affiliation: Department of Radiotherapy, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Irena
authors.initials: I
authors.lastname: Oblak
authors.forename: Vaneja
authors.initials: V
authors.lastname: Velenik
authors.forename: Franc
authors.initials: F
authors.lastname: Anderluh
authors.forename: Barbara
authors.initials: B
authors.lastname: Mozina
authors.forename: Janja
authors.initials: J
authors.lastname: Ocvirk
keywords: preoperative radiochemotherapy; prognostic factors; rectal cancer; tissue inhibitor of metalloproteinases